This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Some studies describe a difference in corpus callosum structure in patients with epilepsies. In addition, there are several studies which describe critical time points on the development of this structure. Epilepsies with well-defined etiology and onset offer an opportunity to examine the effects of early cortical disturbances on the development of the corpus callosum. In this study we want to examine the influence of age of onset of the epilepsy, the duration and lateralization of the seizure focus on the development of the corpus callosum. For this purpose, we performed T1-weighted MRI scans in about 150 patients with temporal lobe epilepsy (left and right hemispheric) as well as about 50 control subjects. All of the patients are clinically well-described in regard to onset of epilepsy, etiology and duration.